Shoe heel and heel reinforcing pin attached tread element therefor



y 26, 1964 H. J. STONE 3,134,180

SHOE HEEL AND HEEL REINFOR G P ATTACHED TREAD ELEMEN H F Filed Nov. 1961 k &

WNTOR.

HERMAN JAMES STONE United States Patent H 3,134,189 SlZ-IUE HEEL AND HEEL REENFORCING PIN ATTACHED 'lREAD ELEMENT THEREFGR Herman Flames Stone, Broclkton, Mass, assignor, by mesne assignments, to The Independent Nail Corporation, Eridgewater, Mass, a corporation of Delaware Filed Nov. 1, 1961, Ser. No. 149,345 4 Claims. (will. EEG-36) such slender lower heel portions are notoriously unsteady t and teetery and damaging to floors and floor coverings and lack sumcient and suitable heel tread engagement for sure-footedness and to withstand the gruelling impact and wear imposed thereon. The heel ends, if hard and rigid, have an undesirable punching effect on floor coverings and even punch holes in some thin light-weight floors.

Heels are preferably and usually made of relatively light materials, such as leather, wood or the like which are shock deadening and not likely to damage surfaces with which they may come in contact. A relatively rigid plastic has been found to be suitable and generally adopted for slenderized shoe heels, but such materials do not have inherent strength to withstand the extraordinarily severe crushing, bending and twisting strains to which shoe heels are subjected in use and it is essential that heels of such materials be reinforced effectively to withstand the strains imposed thereon.

This may be and is acceptably accomplished by the use of a stiff, unbendable metal pin which extends up through the heel from the lower tread end thereof into and is firm- 1y secured in the upper enlarged part of the heel, but the metal pin has the disadvantage that it transmit impact readily to the upper portion of the heel and moreover the lower end of the pin presents a serious problem, as it must be safeguarded with certainty and permanence to avoid protrusion thereof beyond the tread face of the heel. If it protrudes it not only contributes greater tippab lity of the heel on hard surfaces, but it is very damaging and destructive to floors and floor coverings and to other surfaces and articles with which it comes in con tact.

The materials of which such reinforced heels are made necessarily wear away more readily than the metal reinforcing pin end, and quite rapidly on account of the smallness of the tread end area thereof around the 'pin, and such wearing away would leave the pin end protruding therebeyond.

Heels with larger tread areas are commonly provided with a special wear resistant or cushioning tread layer, or top lift as it is commonly referred to, and tough prolonged wear resistant and shock cushioning materials are available which are particularly appropriate for protective application as such top lift to the lower tread end of slenderized heels, but the smallness of the lower ends of the heels does not permit such materials to be secured thereon satisfactorily by conventional or heretofore available methods, and as a solution of the problem of protecting the heel material around the pin against wear and avoiding damaging and destructive exposure of the pin end, and notwithstanding serious disadvantages thereof, metal top lifts have been adopted and are generally used 3,134,180 Patented May 26, 1964 "ice and are secured to the tread end of the heel by the reinforcing pin which is headed for the purpose and has the head thereof countersunk in the metal top lift flush with the bottom of the latter.

While the metal tread lifts do protect the heel material around the pin end against wearing away and may be initially smooth and free of sharp edges or corners which are likely to scratch, mar or otherwise damage surfaces with which they come in contact, and are not initially prohibitively detrimental to floor surfaces and floor coverings, they are potentially damaging and destructive, as they become battered and worn in use and develop sharp edges and burrs which are particularly damaging and destructive to floor surfaces and floor coverings, and snag and tear stockings and other fabrics, and scratch and gouge furniture or other surfaces with which they come in contact.

They also lack desired frictional gripping for surefootedness and are quite slippable on some surfaces, and moreover the sharp impact which they and the reinforc ing pin provide on hard surfaces is readily communicable by the pin to the upper portion of the heel and may cause discomfort and disturbing nerve reaction. Furthermore which is objectionable and annoying to many women and the sharp impact on hard surfaces and sidewise strains thereagainst are communicable directly to the reinforcing pin end may loosen the pin and heel.

The principal objects of the invention are, to minimize the unsuitability and shortcomings of slenderized shoe heels and eliminate disadvantages thereof; to provide an improved shoe heel of pin reinforced type; to reliably equip such heels with a protective top lift or tread element of tough shock dampening damage preventive cushiony material which assures prolonged effectiveness and safety of tread face engagement and prevents injury or damage to articles and materials with which the tread end of the heel may come in contact; to adapt the reinforcing pin end for permanence and security of anchorage thereto of the cushiony material for safe and reliable attachment of the cushiony top lift to the heel by the reinforcing pin thereof; to minimize the punching capability of the reinforcing pin end; to provide adequate and appropriate cushiony material envelopment of the reinforcing pin end to counteract punching effect thereof and prevent exposure of the pin end and opportunity thereof to cause damage; and in general to improve the stability, surefootedness, safety, comfort and serviceability of slenderized heels and eliminate their capability of causing damage, these and other objects being accomplished as pointed out more particularly hereinafter and as shown in the accompanying drawing, in which:

FIG. 1 is a rear View of a shoe having the heel thereof made in accordance with the present invention, a portion of the shoe upper being broken away at the top and the heel reinforcing pin being shown in broken lines;

FIG. 2 is a side view of'the rear portion of the shoe of FIG. 1' and the heel thereof, with a lower portion of the heel broken away to show the reinforcing pin therein;

FIG. 3 is a cross sectional view, greatly enlarged of the lower portion of the heel taken on the line 3-3 of FIG. 2;

r j FIG. 4;

FIG. 6 is a cross sectional view of the reinforcing pin 7 of FIG. 4, taken on the line 66 thereof;

FIG. 7 is an enlarged vertical sectionalview of the lower end portion of the heel taken on the line "i7 of FIG. 3, the lower end portion of the reinforcing pin being shown therein as taken on the line A-A of FIG. 6;

9 ,J FIG. 8 is a sectional view similar to that of FIG. 7, but taken on the line 8-8 of FIG. 3, the lower end of the reinforcing pin being shown therein as taken on the line B-B of FIG. 6; and V F IG. 9 is an enlarged sectional view of a mold for mold ing the heel tread element on the headed end of the reinforcing pin and shows the mutilated flat head of the pin in the mold cavity ready for the molding operation.

Referring to the drawing, the reference numeral 11 indicates a shoe heel, as a whole, of the type to which the invention relates, attached in the usual manner to a shoe 12 of conventional slenderized heel type, pertinent portions only of which are shown in the drawing.

The shoe has the'customary shoe bottom 13, which is usually composed of an assembly of parts providing a relatively stifi, partially flexible support on which the foot rests in an inclined position determined by the height of the shoe heel, and the heel 11 is secured in customary manner to the rear end or heel portion 13 of the shoe bottom and supports the heel portion 13 at a high elevation with the heel portion 13 and the shank portion 13 of the shoe'bottom 13 sloping quite abruptly downward to the forepart 13 of the shoe bottom to support the foot in a corresponding sloped position in the shoe with the ball portion of the foot resting at a low level on the forepart portion 13 of the shoe bottom.

The heel 11 comprises a body of suitable material 14,

for example a relatively rigid plastic such as commonly used for such heels, the body being undercut at the front and rear and opposite sides, as'usual, to form an enlarged heel seat portion 15 at the top with a slender lower heel portion 16 depending therefrom which supports the heel seat portion at the desired highelevation and terminates in a small lower end to which a top lift 17 is secured in accordance with the invention toserve for tread engagement with the ground.

The lowerheel portion of the body is flared upwardly as customary for graceful contour and appropriate merging thereof with the enlarged heel seat portion, the flaring also providing increased structural strength for the upper portion of the :lower heel, and the lower heel is of generally circular form throughout the length thereof with a shallow concave breast 18 at the front. 7 a

The heel is provided at its upper end with a top face or heel seat 19 which is shaped to fit against and sloped to correspond to the slope of the underside of the rear heel end portion 13 of the shoe bottom so that the heel occupies an upright position, as shown in F163. 1 and 2 when the shoe is resting on a level surface indicated by the line 20. j

The lower heel portion is bored or otherwise provided with an opening 21 extending upwardly therein from the bottom and has a one piece nail-like reinforcing pin 22 extending upwardly therein with the upper end portion thereof extending into and firmly secured in a siifiiciently enlarged upper portion of the heel for rigid anchorage therein.

The pin ZZis similar. to a common wire nail andhas 4 and absorb shock effectively and is molded onto the projecting end of the pin in intimate conformity therewith. 7

Such materials are well known and available on the market and readily moldable and adapted for injection molding.

Preferably the stem or shank 25 of the pin is enlarged within the top lift 17 to provide a shoulder at the top face 29 of the top lift, and this may be a local annular enlargement of rounded bulge form, as indicated at 28, which terminates at the top face 29 of the top lift and that face 29 is of substantially the same size as the bottom face 24 of the heel and is jammed thereagainst.

It is important that the pin head occupy a minimum amount of the depth or thickness of the top lift to provide adequate thickness of top lift stock below the pin head for wear and safe coverage of the lower end of the pin, and to provide adequate top lift stock overlying the pin head for security of the top lift on the pin head against stripping off therefrom, and accordingly the pin head is of thin sheet metal like stock, and integral with the stem of the pin for security and preferably formed of extruded pin stock like a nail head for convenience of manufacture, and provides a relatively wide flange around the pin end and extending outward therefrom and of a mutilated form providing a circular series of consecutive flange portions constituting wings as hereafter explained.

The pin head is generally circular to correspond to the circular form of the pillar tip and of as great diameter permissible to provide safe connection therearound of the portion of the top lift above the pin head with the portion of the top lift thereunder, and for security or 1 anchorage of the top lift on the pin head the latter is broad faced elements arranged in the the longitudinal axis of which are indicated at 32 slitted or otherwise divided at intervals therearound in wardly from the outer edge, as indicated SE) to provide aseries of wings or fins around the pin end providing manner of petals on the pin end.

Eight such wings or petals are shown in the illustrative embodiment of the'drawing, alternate ones of which extend outwardly at different levels, four thereof which are indicatedat 31, are considered the lower wings, and extend straight out from the pin end in a plane normal to the pin and the other four of and considered the upper wings, are arranged in alternate relation with the wings 31, and inclined upwardly and outwardly to a level abovethat of the wings 31 so that the greater portion of the radial length'of the wings 32 projects upwardly above the level of the top faces of the lower wings 31.

Thus the alternate Wings at the different elevations provide in effect a multiplicity of elevationally staggered teeth which are embedded in the material of the top lift body with the wide solid portions of the material of the top lift body intervening between the upper wings and also between the lower wings and providing multiple place and reliable keying of the top lift body to the head a stem or shank25 which ispointed at one end as at 26 and provided with a head 27 at the other end, and the stem; or shank thereof, which extends upwardly in the.

ment of the top'lift l7 thereon, and the top lift is of a very tough firrn and wear resistant plastic material of the. general nature of' semi-hard cured rubber and of sufliciently'yieldable and resilient nature to cushion impact upwardly at such slope that the outer extremities of the of the'pin"22 to prevent relative rotation of the top lift and head of thepin.

The relatively broad faces of the Wings also provide wide area gripping of the top lift thereto and the keying and gripping is particularly effective and adequate to preciude relative rotation .01" twisting of the top lift on the stem as the places. of keying and gripping of the top lift material to the wings is disposed quite remotely from the center of any such rotation or twisting, and it is to be noted in this connection that the upper wingsvare tnrned upper wings are only moderately less distant from the longitudinal axis of the stem of the lower wings 31.

Moreover'the slope of the upper wings is such that there is no acute angularity or sharp bending thereof and V no tendency to crack or break and they are readily and 25 than the outer extremities U1 safely formed to the required slope by a simple bending operation.

The slitting or severance places 39 may be arranged radially, or in parallel paired relation as shown herein, with each upper wing 32 having parallel opposite edges, the latter being preferred as it provides desirable wide face engagement with the top lift stock thereabove and secure clamping thereof against the lower end face 24 of the heel. Also it provides a keystone shape for the lower Wings 31 to lock the top lift thereon against outward movement.

The bottom face 33 of the top lift is parallel with and suitably distant from the top face 29 thereof to provide a relatively thick top lift having ample depth for Wear, cushioning and reliability of anchorage of the top lift to the pin, and the horizontal portion of the pin head, which is considered the main'portion thereof and includes the lower Wings 31 is preferably disposed approximately midway between the upper and lower faces 23 and 33 of the top lift so as to provide substantial thickness or depth of top lift stock at 34 below the said main body portion of the pin head and also substantial thickness of top lift stock above the pin head as at 35 to overlie the pin head for security of anchorage of the top lift on the pin head and secure clamping of the top lift against the bottom face 24 of the heel.

Because of the upturned arrangement thereof the upper wings 32 provide broad hook-like elements which have a very effective hook engagement with the top lift at intervals around the pin to safely prevent peeling or stripping of the top lift off of the pin head and when the top lift is clamped firmly against the bottom face 24 of the heel, as it is intended to be, the security of the hook engagement is greatly enhanced. It is to be noted that the upper ends of the upper wings 32 are disposed at a safe distance from the top face 29 of the top lift thereby leaving a substantial thickness of top lift stock therebetween, which together with the increased thickness of toplift stock between the lower wings 31 and top face 29 of the top lift provides a very substantial depth and volume of circularly continuous overhang of the top lift stock over the pin head and that overhanging portion is reliably connected to and unified with the bottom portion 34 of the top lift not. only around the pin head but also through the gaps bet-ween the upturned upper wings 32 and the lower wings 31, insuring direct connection of the top and bottom portions of the heel to one another throughout a wide marginal Zone of the top lift and inseparable unity of the upper and lower portions of the top lift with one another.

By reason of the above anchorage of the top lift 17 to the headed end of the pin 22, the top lift and pin are a dependably inseparable unitary element with cushioned head and stiff metal stem, the latter of which when driven or forced into place in the heel opening 21 clamps the top lift 17 firmly and positively and securely in place against the lower end face 24 of the heel and as the pin is secured and keyed in the opening 21 to assure non-rotatability thereof and the top lift 17 is safely and reliably interlocked with the headed end of the pin against non-rotatability and twisting thereon and stripping therefrom, permanent security of fastening of the top lift on the heel end is assured and also release, displacement or loss of the top lift under the severe strains of shoe use are avoided. The pin 22 is capable of removal, however, from the heel for replacement of the top lift and pin, if necessary, the longitudinal ribbing 23 engagement of the pin with the heel opening 21 permitting the pin .to be withdrawn without multilating the opening and assuring effective non-rotatable replacement of a similar pin in the opening.

Because of the wide area of the bottom of the head of the pin 22 the punching capability of the pin is substantially eliminated and likelihood of punching thereof through the bottom portion of the top lift is reduced to a minimum, and moreover the wideness of the area of 6 the bottom of the pin head and general parallelism thereof with the bottom tread face 33 of the top lift causes general uniformity and flatness of wear of the tread face 33, which is greatly desired as it minimizes damaging punch effect of the tread end of the heel and generally preserves initial flatness and tread area of the bottom face of the heel which prolongs wearability and tends to preserve such stability and non-teeterability as the heel initially had.

Moreover the above described anchorage of the top lift on the pin end assures permanence and adequacy of embedding of the pin end in the cushiony top lift to avoid exposure of the pin end and as the pin end is the only metal part at the tread end of the heel, in accordance with the invention, and is safely protected by the cushiony top lift, the possibility of the small tread end of the heel causing damage to floors or floor coverings is greatly minimized and capability of the heel end to scratch, dent, tear or otherwise cause injury or damage to surfaces, articles or materials with which it comes in contact is eliminated.

In its preferred form the top lift 17 is of a frusto-conical form as shown with the surrounding face 36 thereof sloped outwardly and downwardly at an unobjectionable and pleasing slope which substantially increases the area of the bottom tread face 33 thereof for lessening concentration of wear thereon and assuring greater wearability on that account. It also provides greater heel stability, lessens teeterability thereof, provides greater safety of tread engagement with the ground or other surfaces on which shoes are used, and also has other advantages more particularly pointed out hereafter.

On account of the taper and larger diameter of the top lift at the level where the pin head is located therein than the diameter of the top face 29 of the top lift, the pin head may be of greater over-all diameter without sacrificing required amount of top lift stock therearound, and with the surroundingface 36 sloping as shown in the drawing, the over-all diameter of the pin head may be only slightly less than the diameter of the top lift top face 29, thereby providing a pin head clamping area substantially commensurate with that of the heel end face 24 for increased security of clamping of the top portion of the top lift against the heel end, and also providing a correspondingly larger over-all pin head bottom face for lessened pin end punch effect and increased backing area for the bottom part 34 of the top lift.

Moreover, the frusto-conical form of the top lift provides the top lift with an acute angled margin 37 therearound beyond the immediate Zone of the pin head and this margin has sufficient freedom of unrestrained flexibility to accommodate marginal impact and abuse of the tread face margin without damage thereto and generally protects the dead weight area of the tread face 33 directly below the pin head from abuse.

To provide maximum stiffness with minimum diameter, the pins 22 are preferably of hardened steel made from a medium or high carbon steel which is heat treated, after being completely formed, for proper tempering. However, the pins may be made of low carbon steel and case hardened. j

The manufacture of the pins 22 is particularly convenient and economical, as they may be made, like an ordinary common wire nail, on high speed nail making machines with point and head ready for a final operation which completes the pin head. end thereof. After tempering of the pin, the top lifts are also conveniently and economically applicable on the pins by injection molding in simple gang molds, an individual mold of which is indcated at 38 in FIG. 9, and has a mold cavity 39 of the shape to be given to the top lift.

An opening 40 is provided concentrically with the mold cavity, in the side wall 41 of the mold against which the top face 29 of the top lift is formed, and the stem 25 of the headed pin on which the top lift is to be molded is 7 V inserted in the opening 40, pointed end foremost, until stopped by engagement of the bulge 28 with the entrance to the opening 40 and such engagement positions the headed end of the pin in proper distant position from the opposite sides of the mold cavity.

It is irnportant to seal the opening 40 at the entrance to the mold cavity to prevent flow of the top lift material into the opening around the pin stem in the molding operation, and thereby avoid formation of a flash in the opening around the pin. Such flash would be very objecappended claims.

tionable in the application of the top lift to the heel as it would act as a spacer to prevent driving of the heel pin all the way home and thus prevent direct and positive clamping of the face 29 of the top lift against the end face 24 of the heel which is necessary to avoid over flexing of the top lift plastic which would accelerate failure.

To seal the end of the opening and prevent formation ofsuch flash, the enlargement or bulge 28 is formed therearound at the place of engagement with the opening 40 with a precision shoulder 42 which acts like a poppet valve to plug the end of the opening 40 when the pin 22 is placed in position in the mold for molding the top lift thereon.

As an example of a pin and top lift arrangement which 7 is particularly adapted to accomplish the purposes of this invention, the top lift may be approximately inch in thickness or depth and have a inch diameter top face 2 and a 6 inch diameter bottom or tread face 33, thereby providing a bottom face 33 of approximately 82 percent greater area than a face of the top face 29'di ameter.

The stem of the pin 25 is approximately inch in diameter and the over-all diameter of the pin head 27 is approximately inch and the thickness of the flange thereof from which the Wings 31 and 32 are formed is about & inch. g p

r The wings 32 are bent up to an elevation in which the upper extremities thereof are about inch above the plane of the bottom faces of the wings 31 and slightly more than inch above the plane of the top faces of the wings 31.

Preferably the flange from which the wings 30 and 32 are formed, has the slittings or places of separation 30 extending inwardly toward the stem only part way across the flange, as shown best in PEG. 6, so as to leave a circumferentially continuous annular flange portion extending outwardly from the pin with the wings extending outwardly from this annular flange portion, thereby providing greater width of the wings across the root ends thereof and locating the displacement and bending of the wings 32 away from the wings 31 at places distant from the place of juncture of the flange with the stem 25.

It is preferable also that the pin head be'disposed with the umbent wings 31 about midway between the top and bottom faces of' the top lift to provide about half the depth or thickness of the top lift below the wings 31 and about half the depth or thickness of the top lift above the wings 31, and in the above example there is a depth of top'lift stock of nearly inch above thehighestrex tremities of the upturned wings 32.

it is noteworthy'that although the over-all inch diameter of the pin head, which provides the backing for the clamping of the upper portion of the top lift against the heel end, is only /1 inch less than ,the' inch diameter of the face 29 of the top lift which is clamped by the pin head against the heel and thereby clamped firmly throughout its area against the pillar end, there is, nevertheless ample top lift stock around the pin head at'the intermediate level of the latter in the top lift because of the frusto-conical form of the top lift.

The invention described above and illustrated in the set being spaced apart circumferentially around the stern drawing satisfies a pressing need for improvement in slender heels in respects explained above and accomplishes the recited and pointed out objects of theinvention.

It is to be understood, however, that the invention is heel reinforcing pin for lower heel portions of slender shoe heels, said nail having a stem and a head flange integral therewith at one end and embeddable in a heel top lift to lock the top lift thereon, the head flange com.- prising a circularly continuous central section disposed in a plane substantially normal to the longitudinal axis of the stem andvprojecting transversely of the periphery of the stem substantially uniformly in all directions about the longitudinal axis of the stem, and an outer section encircling the central section and having a circular alternat ing series of thin level and raised wings, all of said wings being of substantially comparable size, each wing having individual integral connection only along'its inner extremity to a corresponding distinct outer extremity of the central section, the level wings being disposed in said' therebetween disposed oppositely to the wings of the other set, and the wings of one set being portions matching the spaces of the other set and projecting away from such last namedspaces, and said level and raised wings collectively comprising a greater portion of said flange than said central section. a

2. A heel top lift and reinforcing unit for a lower heel portion of a slenderized shoe heel and comprising a stiff, sturdy one-piece wire nail of hardened steel havinga stern and a head flange integral with said stem at oneend and comprised of the same material as the stem, and asolid body of tough resilient wear resistant cushiony material disposed in direct full surfaced intimate contact with said head flange, said body having generally parallel top and bottom faces and a surrounding peripheral face and being applicabletop face foremost to a shoe heel end'as a top lift for the shoe heel, the body having said head flange disposed in fully embedded relation having the stern projecting substantially centrally from the top face thereof for application in a lower heel portion of a shoe heel as a combination heel reinforcing and top lift fastener therefor, the said head flange comprising a circularly continu-' ous central section disposed in a plane substantially normal to the longitudinal axis of the stem and projecting transversely of the periphery of the stem substantially uniformly in all directions about the longitudinal axis of the stern, and an outer section encircling the central section and having a circular alternating seriesof thin level and raised Wings which are individually embedded in the body, all of siteend of thestem to a level above the plane of the level wings and constituting a raised set, with the wings of each with spaces'therebetween disposed oppositely to the wings of the other set, and the wings of one set being portions matching the spaces of the other set and projecting away from such last named spaces, and said level and raised flange than said central section.

3. A'unit in accordance with claim 2 and wherein said wings collectively comprising a greater portion of said level wings are keystone shaped with opposite extremities V converging toward one another in a direction toward the stem.

4. A unit in accordance with claim 2 and wherein said stem at a region adjacent the first-named end thereof has an integral annular enlargement between which and the aforesaid first named end of the stern an annular seat is provided and said raised wings extending to positions intercepted by direct radial lines emanating from said seat.

10 References Cited in the file of this patent UNITED STATES PATENTS 2,937,461 Trela May 24, 1960 3,041,744 Brauner July 3, 1962 3,055,125 Ronci Sept. 25, 1962 FOREIGN PATENTS 1,238,402 France July 4, 1960 

1. A ONE-PIECE WIRE NAIL OF HARDENED STEEL SERVING AS A HEEL REINFORCING PIN FOR LOWER HEEL PORTIONS OF SLENDER SHOE HEELS, SAID NAIL HAVING A STEM AND A HEAD FLANGE INTEGRAL THEREWITH AT ONE END AND EMBEDDABLE IN A HEEL TOP LIFT TO LOCK THE TOP LIFT THEREON, THE HEAD FLANGE COMPRISING A CIRCULARLY CONTINUOUS CENTRAL SECTION DISPOSED IN A PLANE SUBSTANTIALLY NORMAL TO THE LONGITUDINAL AXIS OF THE STEM AND PROJECTING TRANSVERSELY OF THE PERIPHERY OF THE STEM SUBSTANTIALLY UNIFORMLY IN ALL DIRECTIONS ABOUT THE LONGITUDINAL AXIS OF THE STEM, AND AN OUTER SECTION ENCIRCLING THE CENTRAL SECTION AND HAVING A CIRCULAR ALTERNATING SERIES OF THIN LEVEL AND RAISED WINGS, ALL OF SAID WINGS BEING OF SUBSTANTIALLY COMPARABLE SIZE, EACH WING HAVING INDIVIDUAL INTEGRAL CONNECTION ONLY ALONG ITS INNER EXTREMITY TO A CORRESPONDING DISTINCT OUTER EXTREMITY OF THE CENTRAL SECTION, THE LEVEL WINGS BEING DISPOSED IN SAID PLANE AND CONSTITUTING A LEVEL SET AND THE RAISED WINGS BEING RAISED IN A DIRECTION TOWARD THE OPPOSITE END OF THE STEM TO A LEVEL ABOVE THE PLANE OF THE LEVEL WINGS AND CONSTITUTING A RAISED SET, WITH THE WINGS OF EACH SET BEING SPACED APART CIRCUMFERENTIALLY AROUND THE STEM WITH SPACES THEREBETWEEN DISPOSED OPPOSITELY TO THE WINGS OF THE OTHER SET, AND THE WINGS OF ONE SET BEING PORTIONS MATCHING THE SPACES OF THE OTHER SET AND PROJECTING AWAY FROM SUCH LAST NAMED SPACES, AND SAID LEVEL AND RAISED WINGS COLLECTIVELY COMPRISING A GREATER PORTION OF SAID FLANGE THAN SAID CENTRAL SECTION. 